🚀 Added (New Features)

• Custom Set Builder Testing Mode: The Custom Set Builder tab now functions as a live recoil testing tool. When toggled ON while the tab is active, the custom X/Y recoil values are applied instead of the selected operator's recoil, allowing real-time dial-in of recoil sets. Switching to any other tab automatically restores normal operator recoil.

📂 File-Level Changes Summary
• MainWindow.xaml: Named TabControl and added SelectionChanged handler for tab tracking.
• MainWindow.xaml.cs: Added UpdateCustomSetState() to sync custom recoil mode with RecoilEngine based on tab focus and toggle state.
• RecoilEngine.cs: Added CustomModeActive, CustomRecoilX, CustomRecoilY fields; HandleRecoilTick() checks custom mode first before falling back to mergedSets lookup.

Lithium/RecoilEngine.cs

@@ -20,6 +20,10 @@ namespace Lua
         private static double _remainderX, _remainderY;
         private static double _jitterMultiplierX, _jitterMultiplierY;
 
+        public static bool CustomModeActive = false;
+        public static double CustomRecoilX = 0;
+        public static double CustomRecoilY = 0;
+
         private static bool IsDown(int key)
         {
             return (GetAsyncKeyState(key) & 0x8000) != 0;
@@ -61,12 +65,19 @@ namespace Lua
         {
             try
             {
+                int now = Environment.TickCount;
+
+                if (CustomModeActive)
+                {
+                    HandleJitter(now);
+                    ApplyRecoil((CustomRecoilX, CustomRecoilY));
+                    return;
+                }
+
                 string setName = OperatorSets.CurrentSet;
 
                 if (!OperatorSets.mergedSets.TryGetValue(setName, out var recoil)) return;
 
-                int now = Environment.TickCount;
-
                 HandleJitter(now);
                 ApplyRecoil(recoil);
             }